How soon after "isolation" would you see someone who had tested positive?

[Ohdoleavemealone]

Just wondering as we have been invited to a friends this weekend. Her isolation ended today but she is suffering some breathlessness when going up stairs.
Would you go or request to postpone?

@gurglebelly

My brother was still testing positive at 18 days, so I definitely would postpone

That doesn't mean he's infectious though, the test could well be picking up left over virus. I think that's why you aren't meant to keep on testing.

Obviously he could be a medical outlier but more likely not